24 research outputs found

    CoMon: Cooperative Ambience Monitoring Platform with Continuity and Benefit Awareness

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    Mobile applications that sense continuously, such as location monitoring, are emerging. Despite their usefulness, their adoption in real-world deployment situations has been extremely slow. Many smartphone users are turned away by the drastic battery drain caused by continuous sensing and processing. Also, the extractable contexts from the phone are quite limited due to its position and sensing modalities. In this paper, we propose CoMon, a novel cooperative ambience monitoring platform, which newly addresses the energy problem through opportunistic cooperation among nearby mobile users. To maximize the benefit of cooperation, we develop two key techniques, (1) continuity-aware cooperator detection and (2) benefit-aware negotiation. The former employs heuristics to detect cooperators who will remain in the vicinity for a long period of time, while the latter automatically devises a cooperation plan that provides mutual benefit to cooperators, while considering running applications, available devices, and user policies. Through continuity- and benefit-aware operation, CoMon enables applications to monitor the environment at much lower energy consumption. We implement and deploy a CoMon prototype and show that it provides significant benefit for mobile sensing applications

    MobiCon: A mobile context-monitoring platform

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    User context is defined by data generated through everyday physical activity in sensor-rich, resource-limited mobile environments.</jats:p

    PowerForecaster: Predicting Smartphone Power Impact of Continuous Sensing Applications at Pre-installation Time

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    Today&apos;s smartphone application (hereinafter &apos;app&apos;) markets miss a key piece of information, power consumption of apps. This causes a severe problem for continuous sensing apps as they consume significant power without users&apos; awareness. Users have no choice but to repeatedly install one app after another and experience their power use. To break such an exhaustive cycle, we propose PowerForecaster, a system that provides users with power use of sensing apps at pre-installation time. Such advanced power estimation is extremely challenging since the power cost of a sensing app largely varies with users&apos; physical activities and phone use patterns. We observe that the time for active sensing and processing of an app can vary up to three times with 27 people&apos;s sensor traces collected over three weeks. PowerForecaster adopts a novel power emulator that emulates the power use of a sensing app while reproducing users&apos; physical activities and phone use patterns, achieving accurate, personalized power estimation. Our experiments with three commercial apps and two research prototypes show that PowerForecaster achieves 93.4% accuracy under 20 use cases. Also, we optimize the system to accelerate emulation speed and reduce overheads, and show the effectiveness of such optimization techniques.

    The immediate upstream region of the 5 0 -UTR from the AUG start codon has a pronounced effect on the translational efficiency in Arabidopsis thaliana

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    ABSTRACT The nucleotide sequence around the translational initiation site is an important cis-acting element for post-transcriptional regulation. However, it has not been fully understood how the sequence context at the 5 0 -untranslated region (5 0 -UTR) affects the translational efficiency of individual mRNAs. In this study, we provide evidence that the 5 0 -UTRs of Arabidopsis genes showing a great difference in the nucleotide sequence vary greatly in translational efficiency with more than a 200-fold difference. Of the four types of nucleotides, the A residue was the most favourable nucleotide from positions À1 to À21 of the 5 0 -UTRs in Arabidopsis genes. In particular, the A residue in the 5 0 -UTR from positions À1 to À5 was required for a high-level translational efficiency. In contrast, the T residue in the 5 0 -UTR from positions À1 to À5 was the least favourable nucleotide in translational efficiency. Furthermore, the effect of the sequence context in the À1 to À21 region of the 5 0 -UTR was conserved in different plant species. Based on these observations, we propose that the sequence context immediately upstream of the AUG initiation codon plays a crucial role in determining the translational efficiency of plant genes

    An Efficient Dataflow Execution Method for Mobile Context Monitoring Applications

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    Abstract—In this paper, we propose a novel efficient dataflow execution method for mobile context monitoring applications. As a key approach to minimize the execution overhead, we propose a new dataflow execution model, producer-oriented model. Compared to the conventional consumer-oriented model adopted in stream processing engines, our model significantly reduces execution overhead to process context monitoring dataflow reflecting unique characteristics of context monitoring. To realize the model, we develop DataBank, an execution container that takes charge of the management and delivery of the output data for the associated operator. We demonstrate the effectiveness of DataBank by implementing three useful applications and their dataflow graphs, i.e., MusicMap, FindMyPhone, and CalorieMonitor. Using the applications, we show that DataBank reduces the CPU utilization by more than 50%, compared to the methods based on the consumer-oriented model; DataBank enables more context monitoring applications to run concurrently. Keywords-context monitoring, dataflow execution, performance I

    Agarose/Spherical Activated Carbon Composite Gels for Recyclable and Shape-Configurable Electrodes

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    Soft electrodes have been known as a key component in the engineering of flexible, wearable, and implantable energy-saving or powering devices. As environmental issues are emerging, the increase of electronic wastes due to the short replacement cycle of electronic products has become problematic. To address this issue, development of eco-friendly and recyclable materials is important, but has not yet been fully investigated. In this study, we demonstrated hydrogel-based electrode materials composed of agarose and spherical activated carbon (agar/SAC) that are easy to shape and recycle. Versatile engineering processes were applied thanks to the reversible gelation of the agarose matrix which enables the design of soft electrodes into various shapes such as thin films with structural hierarchy, microfibers, and even three-dimensional structures. The reversible sol&#8211;gel transition characteristics of the agar matrix enables the retrieval of materials and subsequent re-configuration into different shapes and structures. The electrical properties of the agar/SAC composite gels were controlled by gel compositions and ionic strength in the gel matrix. Finally, the composite gel was cut and re-contacted, forming conformal contact to show immediate restoration of the conductivity
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